[PATCH v12 57/84] KVM: RISC-V: Mark "struct page" pfns accessed before dropping mmu_lock

From: Sean Christopherson
Date: Fri Jul 26 2024 - 20:12:59 EST


Mark pages accessed before dropping mmu_lock when faulting in guest memory
so that RISC-V can convert to kvm_release_faultin_page() without tripping
its lockdep assertion on mmu_lock being held. Marking pages accessed
outside of mmu_lock is ok (not great, but safe), but marking pages _dirty_
outside of mmu_lock can make filesystems unhappy.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/riscv/kvm/mmu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
index 06aa5a0d056d..806f68e70642 100644
--- a/arch/riscv/kvm/mmu.c
+++ b/arch/riscv/kvm/mmu.c
@@ -683,10 +683,10 @@ int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu,
out_unlock:
if ((!ret || ret == -EEXIST) && writable)
kvm_set_pfn_dirty(hfn);
+ else
+ kvm_release_pfn_clean(hfn);

spin_unlock(&kvm->mmu_lock);
- kvm_set_pfn_accessed(hfn);
- kvm_release_pfn_clean(hfn);
return ret;
}

--
2.46.0.rc1.232.g9752f9e123-goog